If the distance to the nearest star is 4.2 light-years, then
A)the star is 4.2 million AU away.
B)the light we see left the star 4.2 years ago.
C)the star must have formed 4.2 billion years ago.
D)the star must be very young.
E)the star must be very old.

Question

Quizplus · Accepted Answer

A light-year is the distance light travels in one year, so if the distance to the nearest star is 4.2 light-years away, it means the light we see from that star left the star 4.2 years ago.

If the Distance to the Nearest Star Is 4